After the LIMIT 7 (and a comma), we have to add our offset (i.e., how many rows we're going to skip to get to the first of the seven we want to show). In your case, you don't know what the offset is, so we have to define it.

We can create a variable ($page, let's say) and multiply it by 7 (and create another variable from that), depending what page we're on. Page 2, for example, where we want to show rows 8-15, would have the URI: http://website.com/index.php?page=2